A masking member is attached to a part of an article (a masking part) to which coating should not be applied. Said masking member can be removed from said part after the curing of said coating film on said article by heating, resulting in said coating film's loss of fluidity. Accordingly, said masking member must be heat resistant during the coating process.
Hitherto, material consisting of thermoplastic resin mixed with inorganic filler has been provided for use in such masking members (TOKKAIHEI 2-126966).
Among thermoplastic resin materials, polyolefin in particular has strong solvent resistance and is mechanically reinforced by being mixed with inorganic filler, increasing its thermal conductivity and thermal resistance, making said masking member reusable.
However, with respect to the above mentioned conventional masking members, even when mixed with an inorganic filler, its maximum thermal resistance is about 100° C., so that in a surface treatment process requiring a higher temperature, said masking member is easily deformed, and not reusable.
As a means to solve the problem as described above in the prior art, a masking member which is made of an engineering plastic has been provided (TOKKAIHEI 5-261323).
Said engineering plastic has a high level of heat resistance and a masking member made of said engineering plastic can withstand temperatures higher than 150° C., so that said masking member can be used repeatedly.
Nevertheless, the faults of said engineering plastics are their poor moldability due to their high softening temperature and low fluidity, and due to their hardness and brittleness a liability to crack or break easily under excessive applied force.